Field of the Disclosure
The present disclosure relates to a display device, and more particularly, to a touch screen-integrated display device. Although the present disclosure is suitable for a wide scope of applications, it is particularly suitable for improving contact characteristics of the touch screen-integrated display device.
Description of Background
With progress of information-oriented society, various types of demands for display devices for displaying image are increasing. Recently, various types of display devices such as a liquid crystal display (LCD) device, a plasma display panel (PDP) device, and an organic light emitting display (OLED) device have been used.
Such display devices are breaking away from the conventional input systems, such as a button, a keyboard and a mouse, and a touch-based input system which allows a user to intuitively and conveniently input information or instructions has been developed.
In order to provide such a touch-based input system, it is required to identify a touch or non-touch of user and exactly detect touch coordinates.
According to the related art, various touch modes such as a resistance film mode, a capacitance mode, an electromagnetic induction mode, an infrared mode, and an ultrasonic mode are provided for touch sensing.
Further, regarding application of a touch screen to a display device, a technology of installing a touch sensor within a display device has been developed. In particular, an in-cell type display device using a common electrode formed on a lower substrate as a touch electrode has been developed.
The display device includes a display panel in which data lines and gate lines are disposed and subpixels defined at intersections between the data lines and the gate lines are disposed, that is, one of the gate lines and one of the data lines define a subpixel. A data driver configured to supply a data voltage to the data lines, a gate driver configured to drive the gate lines, and a controller configured to control the driving timing of the data driver and the gate driver.
A conventional gate driver has been used by manufacturing a separate gate driver IC integrated with a shift register of the gate driver and connecting the gate driver IC to a gate line pad of a display panel through a TCP process or the like.
However, in recent years, a gate-in-panel (GIP) technology of directly forming a shift register of a gate driver on a display panel has been applied.
According to the GIP technology, GIP circuits configured as thin film transistors are formed on a display panel and control signal lines for supplying a clock signal CLK to the GIP circuits are formed together on the display panel.
The control signal lines are formed on a substrate with a gate line. However, in an in-cell touch screen display device, the control signal lines are formed on a passivation layer when a touch sensing line is formed on the passivation layer.
Particularly, one ends of the control signal lines formed on the display panel are connected to signal supply pads formed on the same layer as the gate line in a jumping structure through a pad connection layer.
However, in order to expose the signal supply pads, a contact hole needs to be formed by removing a part of the passivation layer, a gate insulation layer, and a protective layer. However, since the passivation layer has a great thickness, the pad connection layer can be disconnected or cracks because the pad connection layer is disposed on a steep slope of the passivation layer.
Particularly, in a high-temperature and high-humidity environment caused by driving of the display device, micro cracks are easily generated in the pad connection layer to deteriorate image quality.